Resident Dermatologist: Andrew Krispinsky, MD

Attending Dermatologist: Susan Massick, MD

Dermatopathologist: Catherine Chung, MD


An 18 year old male presented with a 3 week history of extremely pruritic patches on his trunk, face, and extremities. Prior history was significant for atopic dermatitis as a child, but he denied active disease for many years. He had been treated with topical corticosteroids, oral prednisone, and diphenhydramine without significant improvement. He denies recent illness or systemic symptoms. Physical examination revealed diffuse pink patches and plaques on the torso.

At low power, there is mild thickening (acanthosis) of the epidermis with changes in the stratum corneum (scale). A mild perivascular infiltrate is present in the superficial dermis.

Mild, focal spongiosis is seen in the dermis, along with parakeratotic mounds in the stratum corneum.

Extravasated erythrocytes are present along the dermal-epidermal junction.

What is the most likely diagnosis?

  1. Allergic contact dermatitis
  2. Pityriasis rosea
  3. Irritant contact dermatitis
  4. Guttate psoriasis
Pityriasis rosea